Adjustable white noise generating device and method based on shift register

Abstract

The invention discloses an adjustable white noise generation device and method based on a shift register, and the device comprises the following modules: a noise sequence generation module which is used for generating a random number sequence; the digital-to-analog conversion module is used for converting the sequence into an analog white noise signal; the programmable filtering module is used for suppressing high-frequency noise; the dynamic modulation module is used for adapting to different interference environment requirements; the output interface module is used for connecting and outputting an interference signal; the low-power-consumption management module is used for managing energy consumption; the beneficial effects of the invention are that according to the technical scheme, low-cost white noise generation is realized by using the single-chip microcomputer, the output frequency spectrum can be dynamically adjusted through software, directional sound source access and low-power-consumption management are supported, the application range is effectively enhanced, and the reliability is high. Noise output by the white noise generating device can be used for acoustic testing, pickup interference, equipment anti-interference evaluation and the like.

Description

Technical Field

[0001] This invention relates to the fields of electroacoustics and information security technology, and in particular to an adjustable white noise generator and method based on a shift register. Background Technology

[0002] In recent years, with the rapid development of electronic technology, various digital products with recording functions have emerged one after another. In some confidential places, criminals use various eavesdropping devices to eavesdrop. These eavesdropping devices are extremely concealed and difficult to prevent. It is precisely because of the emergence and widespread application of these digital products with recording functions and dedicated eavesdropping devices that enterprises, government departments and even individuals often encounter the problem of being maliciously eavesdropped on and recorded. This seriously infringes on people's personal privacy and the secrets of enterprises and government departments.

[0003] Common methods of preventing eavesdropping mainly involve restricting the carrying of eavesdropping devices. However, since most mobile phones and other portable digital products now have recording functions, it is necessary to use anti-eavesdropping devices. These devices use white noise generators to prevent eavesdropping. Existing white noise generators rely on analog circuits or high-performance DSP devices, which are costly, bulky, and lack flexibility. Therefore, an adjustable white noise generator and method based on a shift register were designed. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned problems by designing an adjustable white noise generator and method based on a shift register.

[0005] The technical solution of the present invention to achieve the above objectives is an adjustable white noise generator based on a shift register.

[0006] Includes the following modules:

[0007] The noise sequence generation module is used to generate random number sequences;

[0008] The digital-to-analog converter module is used to convert the sequence into an analog white noise signal;

[0009] A programmable filter module for suppressing high-frequency noise;

[0010] A dynamic modulation module is used to adapt to different interference environments.

[0011] Output interface module, used to connect and output interference signals;

[0012] The low-power management module is used to manage energy consumption.

[0013] As a further description of this technical solution, the noise sequence generation module uses the linear feedback shift register (LFSR) inside the microcontroller to generate a uniformly distributed random number sequence.

[0014] As a further description of this technical solution, the digital-to-analog conversion module converts a digital random sequence into an analog white noise signal through PWM modulation or an external DAC.

[0015] As a further description of this technical solution, PWM modulation uses the linear congruent method to generate a pseudo-random sequence. The amplitude information is encoded by adjusting the duty cycle. The external DAC is selected as an R-2R type or serial interface DAC chip. The external DAC hardware architecture includes a pseudo-random number generator, an SPI / I2C interface for transmitting digital quantities, a reference voltage source, and an operational amplifier buffer for the output to improve the driving capability.

[0016] As a further description of this technical solution, the programmable filtering module utilizes FIR or IIR digital filtering algorithms, combined with a cutoff frequency set by the software, to suppress high-frequency noise and enhance the interference effect in frequency bands sensitive to the human ear.

[0017] As a further description of this technical solution, the dynamic modulation module supports controlling noise intensity, spectrum distribution, and time-domain characteristics through software parameters to adapt to different interference environment requirements.

[0018] As a further description of this technical solution, the output interface module outputs interference signals through a headphone jack, a buzzer, and an audio module, and can also be connected to a directional sound source to achieve far-field interference.

[0019] As a further description of this technical solution, the low-power management module supports energy-saving strategies such as standby mode and timed startup, making it suitable for use in portable device scenarios.

[0020] A method for operating an adjustable white noise generator based on a shift register includes the following steps: inputting a string of random numbers, which are then used by a microcontroller's internal linear feedback shift register to generate a random number sequence. The random number sequence is then converted into an analog white noise signal by a DAC. The analog white noise signal is then processed by a low-pass filtering algorithm, amplified by a power amplifier, and finally played out through a speaker.

[0021] Its beneficial effects are that this technical solution uses a microcontroller to achieve low-cost white noise generation, can dynamically adjust the output spectrum through software, supports directional sound source access and low power consumption management, effectively enhancing the application range. The noise output by the white noise generator of this technical solution can be used for acoustic testing, sound interference pickup, equipment anti-interference evaluation, etc. Attached Figure Description

[0022] Figure 1This is a schematic diagram of the composition of the present invention; Detailed Implementation

[0023] First, let me explain the design intention of this invention. Common anti-eavesdropping methods mainly restrict the carrying of eavesdropping devices. However, since most mobile phones and other portable digital products now have recording functions, it is necessary to use anti-eavesdropping devices. Anti-eavesdropping devices use white noise generators to achieve anti-eavesdropping. Existing white noise generators rely on analog circuits or high-performance DSP devices, which are costly, bulky, and lack flexibility. This invention designs an adjustable white noise generator and method based on a shift register.

[0024] The present invention will now be described in detail, including an adjustable white noise generator based on a shift register, such as... Figure 1 As shown:

[0025] Includes the following modules:

[0026] A noise sequence generation module is used to generate random number sequences; the noise sequence generation module uses the linear feedback shift register (LFSR) inside the microcontroller to generate uniformly distributed random number sequences.

[0027] The digital-to-analog converter module is used to convert the sequence into an analog white noise signal. The digital-to-analog converter module converts the digital random sequence into an analog white noise signal through PWM modulation or an external DAC. The PWM modulation uses the linear congruential method to generate a pseudo-random sequence and encodes the amplitude information by adjusting the duty cycle. The external DAC is an R-2R type or serial interface DAC chip. The external DAC hardware architecture includes a pseudo-random number generator, an SPI / I2C interface for transmitting digital quantities, a reference voltage source, and an operational amplifier buffer for the output to improve the driving capability.

[0028] A programmable filtering module is used to suppress high-frequency noise. The programmable filtering module uses FIR or IIR digital filtering algorithms, combined with the cutoff frequency set by the software, to suppress high-frequency noise and enhance the interference effect in the frequency band sensitive to human ears.

[0029] The dynamic modulation module is used to adapt to different interference environment requirements; the dynamic modulation module supports the control of noise intensity, spectrum distribution and time domain characteristics through software parameters to adapt to different interference environment requirements.

[0030] The output interface module is used to connect and output interference signals; the output interface module outputs interference signals through a headphone jack, a buzzer, and a speaker module, and can also be connected to a directional sound source to achieve far-field interference.

[0031] The low-power management module is used to manage energy consumption. It supports energy-saving strategies such as standby mode and timed start-up, making it suitable for portable device scenarios. The low-power management module includes a power management unit, a power control strategy module, a low-power simulation module, and a dynamic power optimization module.

[0032] The power management unit includes a multi-voltage domain control module, a power path management module, and a reference voltage source optimization module; it dynamically switches the supply voltage (e.g., 1.8V / 3.3V), and works with the DC-DC converter to achieve adaptive voltage regulation, reducing power consumption by more than 40%. The power path management module enables intelligent switching between main power supply and backup battery power supply (e.g., the VBAT pin of STM32), and supports data retention during power outages.

[0033] The power consumption control strategy module adopts a hierarchical sleep mechanism, including sleep mode, stop mode, standby mode, and automatic wake-up unit.

[0034] The low-power analog module dynamically adjusts the ADC sampling rate according to the signal bandwidth and uses the power supply voltage as a reference to avoid power consumption of the internal reference source.

[0035] The following will detail the working method of the adjustable white noise generator based on the shift register, including the following steps: A string of random numbers is input, and the input random numbers are used to generate a random number sequence through the linear feedback shift register inside the microcontroller. Then, the random number sequence is converted into an analog white noise signal through DAC conversion. Next, the analog white noise signal is processed by a low-pass filtering algorithm. After processing, the power amplifier enhances the signal, and the white noise is played through the speaker.

[0036] This technical solution utilizes a microcontroller to achieve low-cost white noise generation. The output spectrum can be dynamically adjusted via software, and it supports directional sound source access and low-power management, effectively expanding its application range. The noise output by the white noise generator in this technical solution can be used for acoustic testing, sound interference pickup, and equipment anti-interference evaluation.

[0037] The above technical solutions only embody the preferred technical solutions of the present invention. Any modifications that may be made by those skilled in the art to certain parts thereof embody the principles of the present invention and fall within the protection scope of the present invention.

Claims

1. An adjustable white noise generator based on a shift register, characterized in that, Includes the following modules: The noise sequence generation module is used to generate random number sequences; The digital-to-analog converter module is used to convert the sequence into an analog white noise signal; A programmable filter module for suppressing high-frequency noise; A dynamic modulation module is used to adapt to different interference environments. Output interface module, used to connect and output interference signals; The low-power management module is used to manage energy consumption.

2. The adjustable white noise generator based on a shift register according to claim 1, characterized in that, The noise sequence generation module uses the linear feedback shift register (LFSR) inside the microcontroller to generate a uniformly distributed random number sequence.

3. The adjustable white noise generator based on a shift register according to claim 1, characterized in that, The digital-to-analog conversion module converts digital random sequences into analog white noise signals through PWM modulation or an external DAC.

4. The adjustable white noise generator based on a shift register according to claim 3, characterized in that, PWM modulation uses a linear congruent method to generate a pseudo-random sequence. The amplitude information is encoded by adjusting the duty cycle. An R-2R type or serial interface DAC chip is selected for the external DAC. The external DAC hardware architecture includes a pseudo-random number generator, an SPI / I2C interface for transmitting digital quantities, a reference voltage source, and an operational amplifier buffer for the output to improve the driving capability.

5. The adjustable white noise generator based on a shift register according to claim 1, characterized in that, The programmable filtering module uses FIR or IIR digital filtering algorithms, combined with the cutoff frequency set by the software, to suppress high-frequency noise and enhance the interference effect in frequency bands sensitive to human hearing.

6. The adjustable white noise generator based on a shift register according to claim 1, characterized in that, The dynamic modulation module supports controlling noise intensity, spectral distribution, and time-domain characteristics through software parameters to adapt to different interference environment requirements.

7. The adjustable white noise generator based on a shift register according to claim 1, characterized in that, The output interface module outputs interference signals through a headphone jack, a buzzer, and a speaker module, and can also be connected to a directional sound source to achieve far-field interference.

8. The adjustable white noise generator based on a shift register according to claim 1, characterized in that, The low-power management module supports energy-saving strategies such as standby mode and scheduled start-up, making it suitable for use in portable devices.

9. A method for operating an adjustable white noise generator based on a shift register as described in any one of claims 1-8, characterized in that, Includes the following steps: A string of random numbers is input, which is then used by the microcontroller's internal linear feedback shift register to generate a random number sequence. The random number sequence is then converted into an analog white noise signal by a DAC. The analog white noise signal is then processed by a low-pass filtering algorithm, amplified by a power amplifier, and played out through a speaker.

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